In an optical network, Wavelength Division Multiplexing (WDM) or Dense Wavelength Division Multiplexing (DWDM) permits the multiplexing of multiple optical carriers onto a single optical fiber by using different wavelengths of laser light. DWDM can carry more optical channels compared to, for example, Coarse Wavelength Division Multiplexing (CWDM). As a result, DWDM is used in optical networks in which denser optical channel spacing is needed. Passive WDMs separate wavelengths using passive optical components.
Optical performance of passive WDM networks presents various challenges to service providers and network providers, such as the collection of performance data, identifying performance issues, remedying failures efficiently in terms of time, cost, resources (e.g., personnel, etc.), etc.